Associations between COVID-19 and hospitalisation with respiratory and non-respiratory conditions: a record linkage study.

OBJECTIVES: To assess associations between SARS-CoV-2 infection and the incidence of hospitalisation with selected respiratory and non-respiratory conditions in a largely SARS-CoV-2 vaccine-naïve population . DESIGN, SETTING, PARTICIPANTS: Self-control case series; analysis of population-wide surveillance and administrative data for all laboratory-confirmed COVID-19 cases notified to the Victorian Department of Health (onset, 23 January 2020 - 31 May 2021; ie, prior to widespread vaccination rollout) and linked hospital admissions data (admission dates to 30 September 2021). MAIN OUTCOME MEASURES: Hospitalisation of people with acute COVID-19; incidence rate ratios (IRRs) comparing incidence of hospitalisations with defined conditions (including cardiac, cerebrovascular, venous thrombo-embolic, coagulative, and renal disorders) from three days before to within 89 days of onset of COVID-19 with incidence during baseline period (60-365 days prior to COVID-19 onset). RESULTS: A total of 20 594 COVID-19 cases were notified; 2992 people (14.5%) were hospitalised with COVID-19. The incidence of hospitalisation within 89 days of onset of COVID-19 was higher than during the baseline period for several conditions, including myocarditis and pericarditis (IRR, 14.8; 95% CI, 3.2-68.3), thrombocytopenia (IRR, 7.4; 95% CI, 4.4-12.5), pulmonary embolism (IRR, 6.4; 95% CI, 3.6-11.4), acute myocardial infarction (IRR, 3.9; 95% CI, 2.6-5.8), and cerebral infarction (IRR, 2.3; 95% CI, 1.4-3.9). CONCLUSION: SARS-CoV-2 infection is associated with higher incidence of hospitalisation with several respiratory and non-respiratory conditions. Our findings reinforce the value of COVID-19 mitigation measures such as vaccination, and awareness of these associations should assist the clinical management of people with histories of SARS-CoV-2 infection.

To intubate or not to intubate? Predictors of inhalation injury in burn-injured patients before arrival at the burn centre.

OBJECTIVE: Inhalation injury occurs in approximately 10-20% of burn patients and is associated with increased mortality. There is no clear method of identifying patients at risk of inhalation injury or requiring intubation in the pre-hospital setting. Our objective was to identify pre-burn centre factors associated with inhalation injury confirmed on bronchoscopy, and to develop a prognostic model for inhalation injury. METHODS: We analysed acute admissions from the Victorian Adult Burns Service and Ambulance Victoria electronic patient care records for 1 July 2009 to 30 June 2016. We defined inhalation injury as an Abbreviated Injury Scale of >1 on bronchoscopy. A multivariable logistic regression prediction model was developed based on pre-burn centre factors. RESULTS: Emergency medical services transported 1148 patients who were admitted to the burn centre. The median age of patients was 39 years and most patients had <10% total body surface area (%TBSA) burned. The prevalence of confirmed inhalation injury was 11%. Increasing %TBSA burned, flame, enclosed space, face burns, hoarse voice, soot in mouth and shortness of breath were predictive of inhalation injury. The model provided excellent discrimination (area under curve 0.87, 95% confidence interval 0.84-0.91). A lower proportion of patients intubated at a non-burn centre had an inhalation injury (33%) compared to patients intubated by emergency medical services (54%) and in the burn centre (58%). CONCLUSIONS: A model to predict inhalation injury in burn-injured patients was developed with excellent discrimination. This model requires prospective testing but could form an integral part of clinician decision-making.

Incidence and Outcomes of Out-of-Hospital Cardiac Arrest in Singapore and Victoria: A Collaborative Study.

Background Incidence and outcomes of out-of-hospital cardiac arrest (OHCA) vary between communities. We aimed to examine differences in patient characteristics, prehospital care, and outcomes in Singapore and Victoria. Methods and Results Using the prospective Singapore Pan-Asian Resuscitation Outcomes Study and Victorian Ambulance Cardiac Arrest Registry, we identified 11 061 and 32 003 emergency medical services-attended adult OHCAs between 2011 and 2016 respectively. Incidence and survival rates were directly age adjusted using the World Health Organization population. Survival was analyzed with logistic regression, with model selection via backward elimination. Of the 11 061 and 14 834 emergency medical services-treated OHCAs (overall mean age±SD 65.5±17.2; 67.4% males) in Singapore and Victoria respectively, 11 054 (99.9%) and 5595 (37.7%) were transported, and 440 (4.0%) and 2009 (13.6%) survived. Compared with Victoria, people with OHCA in Singapore were older (66.7±16.5 versus 64.6±17.7), had less shockable rhythms (17.7% versus 30.3%), and received less bystander cardiopulmonary resuscitation (45.7% versus 58.5%) and defibrillation (1.3% versus 2.5%) (all P<0.001). Age-adjusted OHCA incidence and survival rates increased in Singapore between 2011 and 2016 (P<0.01 for trend), but remained stable, though higher, in Victoria. Likelihood of survival increased significantly (P<0.001) with arrest in public locations (adjusted odds ratio [aOR] 1.81), witnessed arrest (aOR 2.14), bystander cardiopulmonary resuscitation (aOR 1.72), initial shockable rhythm (aOR 9.82), and bystander defibrillation (aOR 2.04) but decreased with increasing age (aOR 0.98) and emergency medical services response time (aOR 0.91). Conclusions Singapore reported increasing OHCA incidence and survival rates between 2011 and 2016, compared with stable, albeit higher, rates in Victoria. Survival differences might be related to different emergency medical services practices including patient selection for resuscitation and transport.

Community lessons to understand resuscitation excellence (culture): Association between emergency medical services (EMS) culture and outcome after out-of-hospital cardiac arrest.

BACKGROUND: The large geographic variation in outcome after out-of-hospital cardiac arrest (OHCA) is not well explained by traditional patient and emergency medical services (EMS) characteristics. A 'culture of excellence' in resuscitation within an EMS is believed to be an important factor that influences quality of care and outcome in patients with OHCA. However, whether a culture of excellence is associated with improved survival after OHCA is not known. METHODOLOGY: We linked survey responses from EMS agency medical directors related to resuscitation culture to a retrospective analysis of prospectively collected data from the Resuscitation Outcomes Consortium (ROC) Epistry - Cardiac Arrest. We used a multivariable random effects model to assess whether EMS culture strategies were associated with OHCA survival to hospital discharge. RESULTS: Of the 46 EMS medical directors surveyed, 35 (76%) provided a complete response. Included were n = 66,597 cases of OHCA who received attempted resuscitation by one of n = 123 EMS agencies from July 1, 2010, through June 30, 2015. Overall survival to discharge was 11%. Organizational values and goals were independently associated with survival to hospital discharge in all OHCAs (adjusted odds ratio [AOR] 1.27, 95% confidence interval [CI] 1.09-1.48) and the subgroup restricted to bystander witnessed OHCAs with initial shockable rhythm (AOR 1.55, 95% CI 1.21-1.99). CONCLUSIONS: An organizational goal to improve OHCA survival was independently associated with improved survival to discharge. EMS agencies looking to improve OHCA survival should consider implementing an organizational goal to improve OHCA survival and empower quality improvement personnel to drive that goal.

The impact of bystander relation and medical training on out-of-hospital cardiac arrest outcomes.

AIM: In this study, we investigate the impact of bystander relation and medical training on survival to hospital discharge in out-of-hospital cardiac arrest (OHCA) patients receiving bystander cardiopulmonary resuscitation (CPR). METHODS: A retrospective analysis was performed on non-traumatic OHCA patients receiving bystander CPR and Emergency Medical Service (EMS) attempted resuscitation from 2015 through 2017. Adjusted logistic regression was used to assess the association between related versus unrelated and layperson versus medically trained bystander CPR providers and survival to hospital discharge. RESULTS: A total of 4464 OHCA were eligible for inclusion, of which 2385 (53.4%) received CPR from a relative, 468 (10.5%) from a work colleague or friend and 1611 (36.1%) from a stranger. Layperson's provided CPR in 3703 (83.0%) OHCA and medically trained professionals in 761 (17.0%). After adjustment for arrest characteristics, there was no difference in survival to hospital discharge between related versus unrelated CPR (adjusted odds ratio [AOR] 0.92, 95% confidence interval [CI]: 0.68-1.23, p = 0.555). However, bystander CPR by a medically trained provider rather than a layperson, was associated with an increase in the odds of survival by 47% (AOR 1.47, 95% CI: 1.09-2.00, p = 0.012) in the overall population and 73% (AOR 1.73, 95% CI: 1.21-2.49; p = 0.003) in patients with an initial shockable arrest. Adjusting for public access defibrillation significantly attenuated the effect of medically trained bystander CPR in initial shockable arrests (AOR 1.42, 95% CI: 0.97-2.07; p = 0.073). CONCLUSION: This study supports ongoing efforts to crowdsource a larger number of first responders with medical training to OHCA patients to assist with the provision of CPR and early defibrillation.

Seasonal Variation in Out-of-Hospital Cardiac Arrest in Victoria 2008-2017: Winter Peak.

Background: Out-of-Hospital Cardiac Arrest (OHCA) incidence and survival rates are known to vary between seasons in some locations. The winter of 2017 saw the highest ever incidence and lowest survival rate of OHCA recorded in Victoria at the time. Seasonal variation of OHCA has not previously been examined in Australia and there may be a significant effect. We aimed to describe the seasonal incidence of OHCA and examine seasonal differences in survival to discharge and 12-month quality of life outcomes. In addition, we investigated whether recent respiratory infection or pre existing respiratory disease influenced OHCA outcomes. Methods: The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify OHCA occurring in Victoria between 2008 and 2017. We examined OHCA characteristics and outcomes between seasons. We then used multivariate logistic regression, adjusting for the Utstein factors, to examine if season, recent respiratory infection or preexisting respiratory disease is associated with survival to discharge and 12-month quality of life. Results: There were 44 973 OHCA cases of which 22 209 received an attempted resuscitation (49.4%). The incidence of OHCA was highest during winter (22 per 100 000 vs. 18 per 100 000 in summer). In winter, survival to discharge was lower for OHCA patients (12.2% vs. 15.9% in summer). Both recent respiratory infection (AOR: 0.67, 95% CI: 0.52 - 0.87) and OHCA occurring during winter (AOR: 0.79 95% CI: 0.70 - 0.91) were associated with lower odds of survival to discharge. Preexisting respiratory disease was associated with lower odds of moderate to good recovery at 12 months (AOR:0.60 95% CI: 0.41 - 0.89). Conclusion: In winter the incidence of OHCA was at its highest and survival to discharge was at its lowest compared to other seasons. Recent respiratory infection was associated with lower odds of survival to discharge. Measures targeted to vulnerable groups, such as preventative public health measures for respiratory infections and the influenza vaccine may reduce the incidence of OHCA and improve survival rates.

Variation in documented inhalation injury rates following burn injury in Australia and New Zealand.

INTRODUCTION: The negative impact of inhalation injuries on in-hospital outcomes for burn patients is well known, but the burns community is yet to form a consensus on diagnostic criteria and clinical definitions. The diagnosis of inhalation injuries is consequently highly subjective. This study aimed to assess the variation in the rate of documented inhalation injury for adult patients in Australian and New Zealand burn units. METHODS: Data for sequential admissions collected from eight adult burn centres across Australia and New Zealand between July 2009 and June 2016 were extracted from the Burns Registry of Australia and New Zealand (BRANZ). Inhalation injury was classified in two ways: (i) a field in the BRANZ data dictionary, and (ii) through a series of International Classification of Disease 10th Revision Australian Modification (ICD-10-AM) codes. Variation in inhalation injury prevalence was assessed using descriptive statistics, funnel plots, logistic regression, and predicted probabilities. RESULTS: There were 11,206 admissions to BRANZ sites over the study period. Inhalation injury prevalence was the highest at Site D (13.1% for the BRANZ field and 11.8% for the ICD-10-AM codes), but there was significant variation between the contributing sites and the inhalation injury classification methods. CONCLUSION: There is significant variation in the prevalence of documented inhalation injury among Australian and New Zealand burns units. The variation in the prevalence of documented inhalation injury across Australian and New Zealand sites reinforces the need for a consensus definition in the diagnosis of these injuries. Further work is required to improve data quality and reconcile the differences between clinical and ICD-10-AM coding prevalence before changes in clinical practice can be recommended from these data.

Factors associated with return to work among survivors of out-of-hospital cardiac arrest.

BACKGROUND: Although out-of-hospital cardiac arrest (OHCA) is a major cause of global mortality, survival rates have increased over the last decade. As such, there is an increasing need to explore long-term functional outcomes of survivors, such as return to work (RTW). METHODOLOGY: We analysed baseline and 12-month follow-up data from the Victorian Ambulance Cardiac Arrest Registry for patients that arrested between 2010 and 2016 who were working prior to their arrest. We also conducted more detailed RTW interviews in a subset of OHCA survivors who arrested between July and September 2017. Factors associated with RTW were assessed using multivariable logistic regression analysis. RESULTS: A total of 884 previously working survivors were included in the analysis, 650 (73%) of whom RTW. Male sex (AOR 1.80; 95%CI: 1.10-2.94), arrests witnessed by emergency medical services (AOR 2.72; 95%CI: 1.50-9.25), discharge directly home from hospital (AOR 4.13; 95%CI: 2.38-7.18) and favourable 12-month health-related quality of life according to the EQ-5D were associated with RTW. Increasing age (AOR 0.97; 95%CI: 0.95-0.98), traumatic arrest aetiology (AOR 0.18; 95%CI: 0.04-0.77), and labour-intensive occupations (AOR 0.44; 95%CI: 0.29-0.66) were associated with decreased odds of RTW. Of the 23 OHCA survivors that participated in the more detailed RTW telephone-interview, 87% RTW. Flexible work hours or modified duties were offered to 74% of participants. Fatigue was the most frequently reported barrier to RTW. CONCLUSION: This is the largest study to collectively examine factors associated with RTW among survivors of OHCA. Although larger qualitative studies are needed, our findings highlight which patients are at risk of not RTW and who may benefit from targeted rehabilitation strategies.

Exercise-related out-of-hospital cardiac arrest in Victoria, Australia.

BACKGROUND: Characteristics and outcomes of exercise-related out-of-hospital cardiac arrests (OHCA) are not well described in Australia. METHODS: This was a retrospective observational study of non-exercise-related aetiology and exercise-related OHCAs from the Victorian Ambulance Cardiac Arrest Registry between 2008 and 2016, including 12-month quality of life data from 2010 to 2016. Exercise-related OHCA was defined as taking place during or within 1 h of at least moderate intensity exercise. Descriptive statistics and adjusted logistic regression analyses were performed. RESULTS: During the study period there were 482 exercise-related and 33,358 non-exercise-related OHCAs. Jogging/running were the most frequent precipitating sports. The incidence rate of exercise-related OHCA was low (<1 per 100,000 person-years). Compared to non-exercise-related aetiology, exercise-related OHCAs were younger (mean 54 versus 70 years, p < 0.001) and more likely to present in an initial shockable rhythm (85% versus 18%, p < 0.001). Bystander CPR, and bystander or EMS defibrillation at any time, were more common among exercise-related arrests (93% versus 38%, p < 0.001 and 91% versus 24%, p < 0.001, respectively). A public access defibrillator was used in 24% of shockable exercise-related OHCAs compared with 4% of non-exercise-related OHCAs (p < 0.001). After adjustment for arrest characteristics, exercise-related OHCAs were more likely to survive to hospital discharge (50% versus 14%, p < 0.001; adjusted odds ratio [AOR] = 1.56, 95% confidence interval [CI] 1.25-1.96, p < 0.001) and survive to 12-months with good functional recovery (72% versus 62%, p = 0.012; AOR = 1.57, 95% CI 1.08-2.28, p = 0.018). CONCLUSIONS: Exercise-related OHCAs were associated with better short- and long-term prognoses compared to non-exercise-related OHCAs. The underlying factors associated with this survival benefit warrant further investigation.

International variation in survival after out-of-hospital cardiac arrest: A validation study of the Utstein template.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) survival varies greatly between communities. The Utstein template was developed and promulgated to improve the comparability of OHCA outcome reports, but it has undergone limited empiric validation. We sought to assess how much of the variation in OHCA survival between emergency medical services (EMS) across the globe is explained by differences in the Utstein factors. We also assessed how accurately the Utstein factors predict OHCA survival. METHODS: We performed a retrospective analysis of patient-level prospectively collected data from 12 OHCA registries from 12 countries for the period 1 Jan 2006 through 31 Dec 2011. We used generalized linear mixed models to examine the variation in survival between EMS agencies (n=232). RESULTS: Twelve registries contributed 86,759 cases. Patient arrest characteristics, EMS treatment and patient outcomes varied across registries. Overall survival to hospital discharge was 10% (range, 6% to 22%). Overall survival with Cerebral Performance Category of 1 or 2 (available for 8/12 registries) was 8% (range, 2% to 20%). The area-under-the-curve for the Utstein model was 0.85 (Wald CI: 0.85-0.85). The Utstein factors explained 51% of the EMS agency variation in OHCA survival. CONCLUSIONS: The Utstein factors explained 51% of the variation in survival to hospital discharge among multiple large geographically separate EMS agencies. This suggests that quality improvement and public health efforts should continue to target modifiable Utstein factors to improve OHCA survival. Further study is required to identify the reasons for the variation that is incompletely understood.

Controversial Issues: Pro Mechanical Cardiopulmonary Resuscitation.

High-quality cardiopulmonary resuscitation, in particular chest compressions, is a key aspect of out-of-hospital cardiac arrest (OHCA) resuscitation. Manual chest compressions remain the standard of care; however, the extrication and transport of patients with OHCA undermine the quality of manual chest compressions and risk the safety of paramedics. Therefore, in circumstances whereby high-quality manual chest compressions are difficult or unsafe, paramedics should consider using a mechanical device. By combining high-quality manual chest compressions and judicious application of mechanical chest compressions, emergency medical service agencies can optimize paramedic safety and patient outcomes.

Paramedic Intubation Experience Is Associated With Successful Tube Placement but Not Cardiac Arrest Survival.

STUDY OBJECTIVE: Paramedic experience with intubation may be an important factor in skill performance and patient outcomes. Our objective is to examine the association between previous intubation experience and successful intubation. In a subcohort of out-of-hospital cardiac arrest cases, we also measure the association between patient survival and previous paramedic intubation experience. METHODS: We analyzed data from Ambulance Victoria electronic patient care records and the Victorian Ambulance Cardiac Arrest Registry for January 1, 2008, to September 26, 2014. For each patient case, we defined intubation experience as the number of intubations attempted by each paramedic in the previous 3 years. Using logistic regression, we estimated the association between intubation experience and (1) successful intubation and (2) first-pass success. In the out-of-hospital cardiac arrest cohort, we determined the association between previous intubation experience and patient survival. RESULTS: During the 6.7-year study period, 769 paramedics attempted intubation in 14,857 patients. Paramedics typically performed 3 intubations per year (interquartile range 1 to 6). Most intubations were successful (95%), including 80% on the first attempt. Previous intubation experience was associated with intubation success (odds ratio 1.04; 95% confidence interval 1.03 to 1.05) and intubation first-pass success (odds ratio 1.02; 95% confidence interval 1.01 to 1.03). In the out-of-hospital cardiac arrest subcohort (n=9,751), paramedic intubation experience was not associated with patient survival. CONCLUSION: Paramedics in this Australian cohort performed few intubations. Previous experience was associated with successful intubation. Among out-of-hospital cardiac arrest patients for whom intubation was attempted, previous paramedic intubation experience was not associated with patient survival.

Paramedic resuscitation competency: A survey of Australian and New Zealand emergency medical services.

OBJECTIVE: We have previously established that paramedic exposure to out-of-hospital cardiac arrest (OHCA) is relatively rare, therefore clinical exposure cannot be relied on to maintain resuscitation competency. We aimed to identify the current practices within emergency medical services (EMS) for developing and maintaining paramedic resuscitation competency. METHODS: We developed and conducted an online cross-sectional survey of Australian and New Zealand EMS in 2015. The survey was piloted by one EMS and targeted at education managers. RESULTS: A total of nine of the 10 EMS responded to the survey. All EMS reported that they provide resuscitation training to paramedics at the commencement of their employment (median 16 h, interquartile range [IQR]: 7-80). With the exception of one EMS that did not provide any refresher training, a median of 4 h (IQR: 1-7) resuscitation training was provided to paramedics annually. All EMS used cardiac arrest simulations and skill stations to train paramedics. Paramedic exposure to OHCA was not taken into account to determine their training needs. Resuscitation competency was tested by EMS: annually (3/9), biennially (4/9) or not at all (2/9). Two EMS used CPR-feedback devices in clinical practice and only one EMS regularly performed formal debriefing after OHCA cases. Barriers to resuscitation competency included: difficulty removing paramedics from clinical duties for training and a lack of paramedic exposure to OHCA. CONCLUSION: All of the surveyed EMS provided initial resuscitation training to paramedics, but competency testing and refresher training practices varied between services. A lack of individual exposure to cardiac arrest and training time were identified as barriers to resuscitation competency.

Paramedic Exposure to Out-of-Hospital Cardiac Arrest Resuscitation Is Associated With Patient Survival.

BACKGROUND: Although out-of-hospital cardiac arrest (OHCA) is a major public health problem, individual paramedics are rarely exposed to these cases. In this study, we examined whether previous paramedic exposure to OHCA resuscitation is associated with patient survival. METHODS AND RESULTS: For the period 2003 to 2012, we linked data from the Victorian Ambulance Cardiac Arrest Registry to Ambulance Victoria's employment data set. We defined exposure as the number of times a paramedic attended an OHCA where resuscitation was attempted in the 3 years preceding each case. Using a multivariable model adjusting for known predictors of survival, we measured the association between paramedic OHCA exposure and patient survival to hospital discharge. During the study period, there were 4151 paramedics employed and 48 291 OHCAs (44% with resuscitation attempted). The median exposure of all paramedics was 2 (interquartile range 1-3) OHCAs/year. Eleven percent of paramedics were not exposed to any OHCA cases. Increased paramedic exposure was associated with reduced odds of attempted resuscitation (P<0.001). In the 3 years preceding each OHCA where resuscitation was attempted, the median exposure of the treating paramedics was 11 (interquartile range 6-17) OHCAs. Compared with patients treated by paramedics with a median of ≤6 exposures during the previous 3 years (7% survival), the odds of survival were higher for patients treated by paramedics with >6 to 11 (12%, adjusted odds ratio 1.26, 95% confidence interval 1.04-1.54), >11 to 17 (14%, adjusted odds ratio 1.29, 95% confidence interval 1.04-1.59), and >17 exposures (17%, adjusted odds ratio 1.50, 95% confidence interval 1.22-1.86). Paramedic years of experience were not associated with survival. CONCLUSIONS: Patient survival after OHCA significantly increases with the number of OHCAs that paramedics have previously treated.

Regions of High Out-Of-Hospital Cardiac Arrest Incidence and Low Bystander CPR Rates in Victoria, Australia.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) remains a major public health issue and research has shown that large regional variation in outcomes exists. Of the interventions associated with survival, the provision of bystander CPR is one of the most important modifiable factors. The aim of this study is to identify census areas with high incidence of OHCA and low rates of bystander CPR in Victoria, Australia. METHODS: We conducted an observational study using prospectively collected population-based OHCA data from the state of Victoria in Australia. Using ArcGIS (ArcMap 10.0), we linked the location of the arrest using the dispatch coordinates (longitude and latitude) to Victorian Local Government Areas (LGAs). We used Bayesian hierarchical models with random effects on each LGA to provide shrunken estimates of the rates of bystander CPR and the incidence rates. RESULTS: Over the study period there were 31,019 adult OHCA attended, of which 21,436 (69.1%) cases were of presumed cardiac etiology. Significant variation in the incidence of OHCA among LGAs was observed. There was a 3 fold difference in the incidence rate between the lowest and highest LGAs, ranging from 38.5 to 115.1 cases per 100,000 person-years. The overall rate of bystander CPR for bystander witnessed OHCAs was 62.4%, with the rate increasing from 56.4% in 2008-2010 to 68.6% in 2010-2013. There was a 25.1% absolute difference in bystander CPR rates between the highest and lowest LGAs. CONCLUSION: Significant regional variation in OHCA incidence and bystander CPR rates exists throughout Victoria. Regions with high incidence and low bystander CPR participation can be identified and would make suitable targets for interventions to improve CPR participation rates.

Paramedic exposure to out-of-hospital cardiac arrest is rare and declining in Victoria, Australia.

BACKGROUND AND OBJECTIVE: Paramedic exposure to out-of-hospital cardiac arrest (OHCA) may be an important factor in skill maintenance and quality of care. We aimed to describe the annual exposure rates of paramedics in the state of Victoria, Australia. METHODOLOGY: We linked data from the Victorian Ambulance Cardiac Arrest Registry (VACAR) and Ambulance Victoria's employment dataset for 2003-2012. Paramedics were 'exposed' to an OHCA if they attended a case where resuscitation was attempted. Individual rates were calculated for average annual exposure (number of OHCA exposures for each paramedic/years employed in study period) and the average number of days between exposures (total paramedic-days in study/total number of exposures in study). RESULTS: Over 10-years, there were 49,116 OHCAs and 5673 paramedics employed. Resuscitation was attempted in 44% of OHCAs. The typical 'exposure' of paramedics was 1.4 (IQR=0.0-3.0) OHCAs per year. Mean annual OHCA exposure declined from 2.8 in 2003 to 2.1 in 2012 (p=0.007). Exposure was significantly less in those: employed part-time (p<0.001); in rural areas (p<0.001); and with lower qualifications (p<0.001). Annual exposure to paediatric and traumatic OHCAs was particularly low. It would take paramedics an average of 163 days to be exposed to an OHCA and up to 12.5 years for paediatric OHCAs, which occur relatively rarely. CONCLUSIONS: Exposure of individual paramedics to resuscitation is low and has decreased over time. This highlights the importance of supplementing paramedic exposure with other methods, such as simulation, to maintain resuscitation skills particularly in those with low exposure and for rare case types.

A systematic review of the effect of emergency medical service practitioners' experience and exposure to out-of-hospital cardiac arrest on patient survival and procedural performance.

BACKGROUND AND OBJECTIVE: Emergency medical service (EMS) practitioners' experience and exposure to out-of-hospital cardiac arrest (OHCA) and advanced life support (ALS) procedures could be an important factor in procedural success and patient survival. We systematically reviewed the literature to examine these associations. METHODOLOGY: We searched for publications using MEDLINE, EMBASE, CINAHL, CENTRAL and Web of Science. We included studies examining any type of EMS practitioner (e.g. paramedics, physicians) and OHCA patients of all ages and aetiologies. Two reviewers independently extracted data. RESULTS: The search identified 1658 citations, of which 11 observational studies of variable quality were included. The majority of studies did not adjust for important confounding factors and reported across different EMS personnel structures. OHCA survival was not consistently associated with various definitions of career experience in three studies, or with previous OHCA exposure in another study. Endotracheal intubation (ETI) was the only ALS procedure examined. Successful ETI placement was associated with the previous number of ETIs performed in four of five studies, but not career experience in three of four studies. Only one study examined OHCA outcome, and reported an increase in survival to hospital discharge when practitioners had high ETI exposure. CONCLUSIONS: There is no clear evidence of an association with EMS practitioner career experience or exposure to OHCA cases and ALS procedures, with the exception of exposure to ETI and successful placement. However, most studies in this field had substantial risk of bias. Therefore, further studies are required before any definitive conclusions can be drawn.

Effectiveness of the Valsalva Manoeuvre for reversion of supraventricular tachycardia.

BACKGROUND: Patients with the cardiac arrhythmia supraventricular tachycardia (SVT) frequently present to clinicians in the prehospital and emergency medicine settings. Restoring sinus rhythm by terminating the SVT involves increasing the refractoriness of AV nodal tissue within the myocardium by means of vagal manoeuvres, pharmacological agents or electrical cardioversion. A commonly used first-line technique to restore the normal sinus rhythm (reversion) is the Valsalva Manoeuvre (VM). This is a non-invasive means of increasing myocardial refractoriness by increasing intrathoracic pressure for a brief period, thus stimulating baroreceptor activity in the aortic arch and carotid bodies, resulting in increased parasympathetic (vagus nerve) tone. OBJECTIVES: To assess the evidence of effectiveness of the Valsalva Manoeuvre in terminating supraventricular tachycardia. SEARCH METHODS: We electronically searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 1 of 12, 2012); MEDLINE Ovid (1946 to January 2012); EMBASE Ovid (1947 to January 2012); Web of Science (1970 to 27 January 2012); and BIOSIS Previews (1969 to 27 January 2012). Trials registries, the Index to Theses and the bibliographies of all relevant publications identified by these strategies were also checked. SELECTION CRITERIA: We included all randomised controlled trials (RCTs) that examined the effectiveness of the Valsalva Manoeuvre in terminating SVT. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data using a standardised form. Each trial was assessed for internal validity with differences resolved by discussion. Data were then extracted and entered into Review Manager 5.1 (RevMan). MAIN RESULTS: We identified three randomised controlled trials including 316 participants. All three studies compared the effectiveness of VM in reverting SVT with that of other vagal manoeuvres in a cross-over design. Two studies induced SVT within a controlled laboratory environment. Participants had ceased all medications prior to engaging in these studies. The third study reported on patients presenting to a hospital emergency department with an episode of SVT. These patients were not controlled for medications or other factors prior to intervention.The two laboratory studies demonstrated reversion rates of 45.9% and 54.3%, whilst the clinical study demonstrated reversion success of 19.4%. This discrepancy may be due to methodological differences between studies, the effect of induced SVT versus spontaneous episodic SVT, and participant factors such as medications and comorbidities. We were unable to assess any of these factors further, nor adverse effects, since they were either not described in enough detail or not reported at all.Statistical pooling was not possible due to heterogeneity between the included studies. AUTHORS' CONCLUSIONS: We did not find sufficient evidence to support or refute the effectiveness of the Valsalva Manoeuvre for termination of SVT. Further research is needed and this should include a standardised approach to performance technique and methodology.

Drowning related out-of-hospital cardiac arrests: characteristics and outcomes.

AIM: There are few studies on drowning-related out-of-hospital cardiac arrest (OHCA) in which patients are followed from the scene through to hospital discharge. This study aims to describe this population and their outcomes in the state of Victoria (Australia). METHODS: The Victorian Ambulance Cardiac Arrest Registry was searched for all cases of OHCA with a precipitating event of drowning attended by emergency medical services (EMS) between October 1999 and December 2011. RESULTS: EMS attended 336 drowning-related OHCA during the study period. Cases frequently occurred in summer (45%) and the majority of patients were male (70%) and adult (77%). EMS resuscitation was attempted on 154 (46%) patients. Of these patients, 41 (27%) survived to hospital arrival and 12 (8%) survived to hospital discharge (5 adults [6%] and 7 [12%] children). Few patients were found in a shockable rhythm (6%), with the majority presenting in asystole (79%) or pulse-less electrical activity (13%). An initial shockable rhythm was found to positively predict survival (AOR 48.70, 95% CI: 3.80-624.86) while increased EMS response time (AOR 0.73, 95% CI: 0.54-0.98) and salt water drowning (AOR 0.69, 95% CI: 0.01-0.84) were found to negatively predict survival. CONCLUSIONS: Rates of survival in OHCA caused by drowning are comparable to other OHCA causes. Patients were more likely to survive if they did not drown in salt water, had a quick EMS response and they were found in a shockable rhythm. Prevention efforts and reducing EMS response time are likely to improve survival of drowning patients.